Turgor Pressure

Turgor Pressure Lab Background: Plant cells are surrounded by rigid cellulose walls, (unlike animal cells), but plant cells still take in water through their cell membranes. However, plant cells do not burst because their cellulose cell walls limit how much water can move in. The water exerts pressure, called turgor pressure, against the cell wall as the cells take up water. Turgor pressure is like the air pressure of an inflated tire. INSTRUCTIONS Part I: Anacharis Cells Observation 1 1. Place one anacharis leaf on a clean slide. 2. Place one drop of distilled water on the leaf and cover with a cover slip. 3. Observe the leaf under the microscope. 4. Draw, color and label (cell membrane, cell wall, chloroplasts) the cells on 40x, 100x, OR 400x magnification. Choose the best view. Observation 2 1. Place two drops of salt water at the edge of the cover slip. 2. Place a torn piece of paper towel right at the edge of the opposite side of the cover slip. This will draw the salt water under the cover slip toward the paper towel, covering the leaf. 3. The salt water will cause the water to leave the plant cell. 4. Observe the leaf under the microscope. Watch the leaf to observe any changes. 5. Describe what happened to the leaf over a few minutes. 6. Draw, color and label (cell wall, chloroplasts, cell membrane) the dehydrated anacharis cells on 40x, 100x or 400x magnification. Choose the same magnification as your previous drawing. Observation 3 1. Place two drops of distilled water on the edge of the cover slip. 2. Use a torn piece of paper towel to draw the water under the cover slip just like before. 3. Observe the leaf under the microscope. 4. Describe what happened to the leaf over a few minutes. 5. Draw, color and label (cell wall, chloroplasts, cell membrane) the dehydrated anacharis cells on 40x, 100x or 400x magnification. Choose the same magnification as your previous drawing. Part II: Potato 1. Observe the potato piece that has been in distilled water overnight. Describe the way it looks and feels. 2. Observe the potato piece that has been in salt water overnight. Describe the way it looks and feels. CONCLUSION QUESTIONS 1. What happened to the water in the cells when the leaf was covered in salt water? 2. What happened to the water in the cells when the leaf was covered in distilled water? 3. How did the pieces of potato compare? What caused the difference? 4. Which kind of water would increase the turgor pressure? 5. What would a plant do if you put salt water on it? 6. What would a plant do if you did not water it for several days? 7. If you leave your lettuce in the refrigerator for a few days, it gets soft. What could you do to make it more crisp?